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OCEANSIDE: Edison estimates $2.5 billion to retrofit San Onofre

North County Times (2009-08-08) PAUL SISSON

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New cooling system would mean more towers in coastal reserve

Reducing the San Onofre Nuclear Generation Station's thirst for salt water would cost about $2.5 billion and require an untenable amount of construction under one of the region's busiest freeways, according to recent estimates released by the power plant's majority owner.

The plant, which now relies on massive amounts of seawater to cool the steam that spins its electrical generators, is looking at an alternative cooling method in response to a draft policy released June 30 by the state water quality control board. The panel wants all coastal power plants to cut their water intake by 95 percent to reduce the number of fish and fish eggs killed by the cooling process.

The policy, which is up for public comment at a hearing in Sacramento set for Sept. 16, recommends that San Onofre install cooling towers to manage heat released inside the plant rather than use a continuous stream of ocean water to do so.

David Kay, environmental manager for Southern California Edison, which owns and operates San Onofre, said Tuesday that preliminary results of an ongoing engineering study show that idea would probably require installing 32 cooling towers spread across two plots of land east and west of Interstate 5.

Installing the towers, Kay said, would probably require boring up to eight 12-foot-diameter tunnels under the busy freeway.

He added that engineers have also determined that a giant underground water holding vessel called a water box would need to be reinforced, and that there does not appear to be enough room to get the job done.

Combined with the idea of drilling under I-5, Kay said converting the plant to a new cooling system looks difficult if not impossible.

"Even if it were shown to be feasible, the cost is so high, I don't know that Edison would want ---- or that the (California) Public Utilities Commission would approve ---- passing that cost on to our customers," Kay said.

California Coast Keeper, a statewide nonprofit environmental advocacy group, has pushed hard for the new cooling regulations, particularly at seaside plants like San Onofre and the Diablo Canyon plant in Central California.

Angela Haren, the organization's program director, said Wednesday that she believes engineers can find a way to design a less harmful cooling system for the plant, despite the cost and space issues listed by Edison.

"Other nuclear plants have been cost-effectively and -efficiently retrofitted," Haren said. "San Onofre and Diablo Canyon nuclear plants will be able to do the same."

A new rule

The draft policy recently released by the California Water Resources Control Board would affect 19 coastal power plants that use ocean water in a process called "once-through cooling." In addition to San Onofre, the Encina Power Plant in Carlsbad would be affected by the change.

The cooling technique draws large volumes of water ---- 1.6 billion gallons per day at San Onofre ---- into a plant using the cold ocean water to cool steam used to turn turbines. The water is then quickly discharged back into the briny blue whence it came.

Because such large volumes of water are being moved, the process sucks in fish, fish larvae and other marine life, killing an estimated 28,700 pounds of fully grown fish and about 6.8 billion larval fish.

While that amount may seem like a lot, a study that compared commercial fishing rates to the plant's fish kill found that San Onofre's cooling system likely represents 0.02 percent of the California fishery harvest.

Closed-cycle cooling, by comparison, moves much less water and is the preferred method enshrined in the state water board's new cooling policy. Using cooling towers that use evaporation to cool steam, closed-cycle cooling is estimated to need only 5 percent of the ocean water that once-through cooling uses. Less water entering the plant means less aquatic life killed.

A state-funded study published in February 2008 and written by Tetra Tech, a Pasadena-based environmental consulting firm, suggested such a process is feasible at San Onofre, but Edison officials said that study was flawed.

The Tetra Tech study estimated that Edison could accomplish closed-cycle cooling by installing a dozen 62-foot-tall cooling towers north and south of the existing plant. Six could be built in a company parking lot north of the plant, and six more could be built on about 18 acres of blufftop state parkland immediately south of San Onofre. The upgrade, the study estimates, would cost about $1.2 billion, far less than Edison's estimate.

Edison said the study didn't account for the fact that the 18-acre parcel of park property would not be available, forcing San Onofre to locate half of the cooling towers on a "mesa" parcel it owns east of I-5.

"What Tetra Tech didn't know was that when we originally permitted the plant with the (California) Coastal Commission, we committed that we would never develop the bluff south of where the plant is," Kay said. "That means we would have to go under the freeway, and that is where the extra cost comes from."

San Onofe's water intakes are designed to draw from deep water more than 1,000 feet off shore and special caps have been installed to reduce the number of fish that are sucked into the plant.

Peter Douglas, executive director of the California Coastal Commission, said he remembers Edison's promise to preserve the remaining bluffs around San Onofre. He said a legal battle in the late 1970s and early 1980s over expansion of the plant from one reactor to three resulted in the promise not to gobble up any more blufftop real estate.

"The loss of the bluffs was one of the main reasons why the Coastal Commission initially denied the first permit to expand," Douglas said. "One of the trade-offs was to protect the remainders of the bluffs in perpetuity."

Other fish-saving measures

Douglas noted Wednesday that his agency already required Edison to spend millions building artificial reefs and restoring fish habitat in the San Dieguito Lagoon as compensation for the marine life that San Onofre kills. He said it would be difficult for the commission to sanction taking the bluffs to eliminate a problem that it feels has already been paid for.

"As far as we're concerned, those impacts have been addressed," Douglas said.

That may be, said Haren, the California Coast Keeper program director. But state water quality law requires coastal power plants to use the least-harmful cooling technology possible, regardless of whether they have built kelp beds or lagoons to make good with Mother Nature.

She said it does not make sense to grant the state's two largest nuclear plants a mulligan on the new cooling requirements just because implementing them will be expensive or difficult.

"The two nuclear plants withdraw the most water and kill the most fish of all the once-through cooled plants in California," she said. "For a state policy on once-through cooling to be successful, it must include these plants."

Call staff writer Paul Sisson at 760-901-4087 or


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Title OCEANSIDE: Edison estimates $2.5 billion to retrofit San Onofre
Publisher North County Times
Pub Date 2009-08-08
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Note SCE says once-thru upgrades will cost $2.5 billion
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Topic revision: r1 - 2012-10-24, RaymondLutz
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